// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_DEBUG_LIVEEDIT_H_
#define V8_DEBUG_LIVEEDIT_H_

#include <vector>

#include "src/globals.h"
#include "src/handles.h"

namespace v8 {
namespace debug {
    struct LiveEditResult;
}
namespace internal {

    class Script;
    class String;
    class Debug;
    class JavaScriptFrame;

    struct SourceChangeRange {
        int start_position;
        int end_position;
        int new_start_position;
        int new_end_position;
    };

    /**
  Liveedit step-by-step:
  1. calculate diff between old source and new source,
  2. map function literals from old source to new source,
  3. create new script for new_source,
  4. mark literals with changed code as changed, all others as unchanged,
  5. check that for changed literals there are no:
    - running generators in the heap,
    - non droppable frames (e.g. running generator) above them on stack.
  6. mark the bottom most frame with changed function as scheduled for restart
     if any,
  7. for unchanged functions:
    - deoptimize,
    - remove from cache,
    - update source positions,
    - move to new script,
    - reset feedback information and preparsed scope information if any,
    - replace any sfi in constant pool with changed one if any.
  8. for changed functions:
    - deoptimize
    - remove from cache,
    - reset feedback information,
    - update all links from js functions to old shared with new one.
  9. swap scripts.
 */

    class V8_EXPORT_PRIVATE LiveEdit : AllStatic {
    public:
        static void InitializeThreadLocal(Debug* debug);

        // Restarts the call frame and completely drops all frames above it.
        static bool RestartFrame(JavaScriptFrame* frame);

        static void CompareStrings(Isolate* isolate, Handle<String> a,
            Handle<String> b,
            std::vector<SourceChangeRange>* diffs);
        static int TranslatePosition(const std::vector<SourceChangeRange>& changed,
            int position);
        static void PatchScript(Isolate* isolate, Handle<Script> script,
            Handle<String> source, bool preview,
            debug::LiveEditResult* result);
        // Architecture-specific constant.
        static const bool kFrameDropperSupported;
    };
} // namespace internal
} // namespace v8

#endif // V8_DEBUG_LIVEEDIT_H_
